Modern track vehicles, such as the Abrams tank or Bradley fighting vehicle, can weigh in excess of 71 tons and have tracks whose bushing failures can be a major share of track repair and replacement costs, particularly, with deployment of heavy, fast track vehicles to hot climates, e.g., desert or desert-like environments. These bushing failures appear to be due largely to the detrimental effect of heat on bushing rubber, such heat originating from backer hysteresis as well as the external environment.
The backer, which is part of a track vehicle's rubber/metal track providing a path for a roadwheel to traverse in the undercarriage of the track vehicle, is subjected to repeat cyclic loadings as each roadwheel traverses the track segment and the track pads contact ground. Since the 1980's, it has been conventional to use backers based on styrene-butadiene rubber (“SBR”). These backers, while proven to be acceptable for low speed, lighter track vehicles operating in cool climates, are unsuitable for heavier, faster track vehicles deployed in hot climates due to the effect on bushing rubber. In addition, deterioration of the backer itself can be problematic under such conditions, which further adds to track repair and replacement costs. Backer failures can be due to heat build-up and/or may occur by tearing, chunking and abrading, for example.
Accordingly, it would thus be desirable to provide a track segment with a rubber based backer that will provide a desirable balance of low heat build-up under heavy dynamic cyclic compression conditions, and also have a desirable load carrying capability, high heat resistance, and good cut/tear strength in hot climates.